A
binary symmetric channel (or BSC) is a common
communications channel model used in
coding theory and
information theory. In this model, a transmitter wishes to send a
bit (a zero or a one), and the receiver receives a bit. It is assumed that the bit is
usually transmitted correctly, but that it will be "flipped" with a small
probability (the "crossover probability"). This channel is used frequently in information theory because it is one of the simplest channels to analyze.